Journal ArticleDOI
Plastic Deformation of Crystalline Polymers: The Role of Cavitation and Crystal Plasticity
Andrzej Pawlak,Andrzej Galeski +1 more
Reads0
Chats0
TLDR
In this paper, the authors used a small-angle X-ray scattering (SAXS) and density measurements in poly(methylene oxide) (POM), polypropylene (PP), polyamide 6 (PA 6), low-density polyethylenes (LDPEs), and ethylene−octene copolymer (EOC).Abstract:
Plane strain compression in a channel die is kinematically very similar to drawing; however, the possibility of void formation is limited due to a compressive component of stress. In drawing, voids were detected by small-angle X-ray scattering (SAXS) and density measurements in poly(methylene oxide) (POM), polypropylene (PP), and high-density polyethylene (HDPE), but no voiding was found in polyamide 6 (PA 6), low-density polyethylenes (LDPEs), and ethylene−octene copolymer (EOC). The slope and shape of the initial elastic part of true stress−true strain curves are similar in tension and in channel die compression. When drawn samples of POM, PP, HDPE, and PA 6 already show yielding, the channel die compressed samples still undergo elastic deformation to a much larger deformation and respond with a much larger stress. Channel die compressed POM, PP, HDPE, and PA 6 exhibit strong and rapid strain hardening up to 400 MPa in contrast to their behavior in tension. The difference in strain hardening is related ...read more
Citations
More filters
Journal ArticleDOI
Cavitation during deformation of semicrystalline polymers
TL;DR: In this article, the cavitation phenomenon is observed during deformation in many semicrystalline polymers above their glass transition temperature, which is observed only in tension, never during compression or shearing.
Journal ArticleDOI
Cavitation during Tensile Deformation of Polypropylene
Andrzej Pawlak,Andrzej Galeski +1 more
TL;DR: In this paper, the cavitation process of polypropylene was studied and it was shown that cavities appear in the center of a sample shortly before yielding, and with increasing deformation the cavities change their size, number, and orientation from elongated perpendicular to parallel to deformation.
Journal ArticleDOI
Cavitation during tensile deformation of high-density polyethylene
TL;DR: In this paper, the authors studied the cavitation process of high-density polyethylene during tensile deformation and found that the shape of voids is strictly connected with deformation of crystalline phase around them.
Journal ArticleDOI
New insight on initiation of cavitation in semicrystalline polymers: in-situ SAXS measurements
TL;DR: In this article, the authors focused on the initiation of cavitation and on the nucleation rate of polyethylene and found that cavitation can be avoided or, on the contrary, appears before or after yielding.
Journal ArticleDOI
Structural evolution of tensile deformed high-density polyethylene at elevated temperatures: Scanning synchrotron small- and wide-angle X-ray scattering studies
Zhiyong Jiang,Yujing Tang,Jens Rieger,Hans-Friedrich Enderle,Dieter Lilge,Stephan V. Roth,Rainer Gehrke,Zhonghua Wu,Zhihong Li,Yongfeng Men +9 more
TL;DR: In this paper, the structural evolution of an ice-quenched high-density polyethylene (HDPE) subjected to uniaxial tensile deformation at elevated temperatures was examined as a function of the imposed strains by means of combined synchrotron small-angle X-ray scattering (SAXS) and wideangle Xray scattering techniques.
References
More filters
Book
An introduction to the mechanical properties of solid polymers
I. M. Ward,D. W. Hadley +1 more
TL;DR: In this article, the authors discuss the properties of linear Viscoelastic Behaviour as a function of frequency and temperature, and investigate the relationship between the frequency and the temperature.
Journal ArticleDOI
Spherulitic Crystallization from the Melt. I. Fractionation and Impurity Segregation and Their Influence on Crystalline Morphology
H. D. Keith,F. J. Padden +1 more
TL;DR: In this paper, a systematic study of impurity segregation in spherulitic crystallization is described, in which the role of impurities is fulfilled by stereoirregular molecules or by molecules of low molecular weight.
Journal ArticleDOI
Strength and toughness of crystalline polymer systems
TL;DR: The role of crystal plasticity in achieving high toughness is addressed in this article, where two possibilities of the modification of crystal thickness are described: increase in the crystal thickness and a reduction in the number of mobile dislocations in polymer crystals, and two examples of efficient toughening in multicomponent polypropylene systems connected with cavitation are described.
Journal ArticleDOI
Network Stretching, Slip Processes, and Fragmentation of Crystallites during Uniaxial Drawing of Polyethylene and Related Copolymers. A Comparative Study
TL;DR: In this paper, a comprehensive study on a series of polyethylene (PE) samples encompassing a large range of crystallinities was carried out using a video-controlled tensile testing machine.
Journal ArticleDOI
Toughenability of polymers
Ali S. Argon,Robert E. Cohen +1 more
TL;DR: In this paper, the authors demonstrate that all solid polymers are intrinsically brittle and will undergo a ductile to brittle fracture transition based on the nature of their bonding alone, and that the most effective way of avoiding a brittle to brittle transition is to reduce the plastic resistance to delay reaching the brittle strength which is governed by intrinsic cavitation.